Hypothesis Testing Assignment and Quiz 90%

What is the alternative hypothesis, Ha, for this situation?

b

A study investigated the job satisfaction of teachers allowed to choose supplementary curriculum for their classes versus teachers who were assigned all curricular resources for use in their classes. The authors of the study wanted to know if the two groups of teachers had different levels of job satisfaction. They will use a significance level of 5% for their test.Upper-Tail Valuesa5%2.5%1%Criticalz-values1.651.962.58What is (are) the critical value(s) for z in this study? -1.65 and 1.65 -1.96 and 1.96 1.65 1.96

-1.96 and 1.96

A researcher collated data on Americans' leisure time activities. She found the mean number of hours spent watching television each weekday to be 2.7 hours with a standard deviation of 0.4 hours. Jonathan believes that his football team buddies watch less television than the average American. He gathered data from 15 football teammates and found the mean to be 2.3. Which of the following shows the correct z-statistic for this situation? -3.87 -0.26 3.23 5.22

-3.87

Brett is performing a hypothesis test in which the population mean is 310 and the standard deviation is 20. His sample data has a mean of 295 and a sample size of 50. Which of the following correctly depicts the z-statistic for Brett's data? -5.30 -0.11 4.28 6.27

-5.30

A popular video game claims that the average time needed to reach level 10 Paladin is 3 hours with a standard deviation of 0.4 hours. James thinks that he and his four friends are more skilled than the average gamer because it took them an average of only 2.5 hours. Which of the following is the most restrictive level that would validate his claim? 1% 2.5% 5% 10%

1%

The owners of an eyeglass store claim that they fill customers' orders, on average, in 60 minutes with a standard deviation of 15.9 minutes. Based on a random sample of 40 orders, a reporter determines a mean order time of 63 minutes. Let µ represent the average number of minutes to fill an order. To the nearest hundredth, the z-statistic is

1.19

The reporter wants to test the store's claim against the alternative hypothesis that the wait time is actually greater than 60 minutes. What is the critical value for z for a hypothesis test using a 5% significance level?z* =

1.65

A company claims that its packages of beads contain, on average, 50 beads with a standard deviation of 5.4 beads. In a hypothesis test of this claim, H0 is µ = 50 and Ha is µ ≠ 50, where µ is the average number of beads per package. Based on a sample of 20 packages, Celia calculates a mean of 52.5 beads per package. Formula for z-statistic: What is the z-statistic for the sample? Round the answer to the nearest hundredth.z =

2.07

A consumer protection group randomly checks the volume of different beverages to ensure that companies are packaging the stated amount. Each individual volume is not exact, but a volume of iced tea beverages is supposed to average to 300 mL with a standard deviation of 3 mL. The consumer protection group sampled 20 beverages and found the average to be 298.4 mL. Which of the following is the most restrictive level of significance on a hypothesis test that would indicate the company is packaging less than the required average 300 mL? 1% 2.5% 5% 10%

2.5%

A recent survey of 8,000 high school students found that the mean price of a prom dress was $195.00 with a standard deviation of $12.00. Alyssa thinks that her school is more fashion conscious and that students spent more than $195.00. She collected data from 20 people in her high school and found that the average price spent on a prom dress was $208.00. Which of the following are the correct null hypothesis and alternate hypothesis? H0: ; Ha: H0: ; Ha: H0: ; Ha: H0: ; Ha:

H0 = 195; Ha > 195

David wants to complete a hypothesis test with the least amount of probability for error. If he sets the significance level to 1%, assuming his sample is truly random, what else could he adjust in the test in order to reduce error? He could change the population mean. He could increase the sample size. He could change the population standard deviation. He could decrease the sample size.

He could increase the sample size.

A recent survey of 8,000 high school students found that the mean price of a prom dress was $195.00 with a standard deviation of $12.00. Alyssa thinks that her school is more fashion conscious and spent more than $195.00. She collected data from 20 people in her high school and found that the average price spent on a prom dress was $208.00. Which of the following is the correct z-statistic for this situation? 0.24 4.84 7.51 96.90

NOT: 0.24

Tyesha found that the z-statistic was 2.1 and that the critical z-values were -1.96 and 1.96. Which of the following is a valid conclusion based on these results? One can reject the null hypothesis. One can reject the alternate hypothesis. One can accept the null hypothesis. One cannot accept or reject the null hypothesis.

One can reject the null hypothesis.

A study investigated the job satisfaction of teachers allowed to choose supplementary curriculum for their classes versus teachers who were assigned all curricular resources for use in their classes. On average, when surveyed regarding job satisfaction, teachers give a score of 3.3 out of 5 with a standard deviation of 0.6. When the authors of the study interviewed 40 teachers who supplemented with their own materials, they found 3.5 to be the mean. The authors wanted to know if the group of teachers that could choose supplementary curriculum had a higher level of job satisfaction. They used a significance level of 1%. Which of the following statements is valid based on the results of the test? The data shows that teachers allowed to choose supplementary curriculum for classes are more satisfied with their jobs. The data shows that teachers who were assigned all curricular resources for classes are more satisfied with their jobs. The data shows that there is no difference in job satisfaction between the two groups of teachers. The data shows that the authors cannot make a determination either way with this data.

The data shows that the authors cannot make a determination either way with this data.

The critical value for z* for a hypothesis test of the claim at 5% significance is z* = 1.96. How should the z-statistic for the sample be interpreted in terms of the hypothesis test? The null hypothesis should be rejected. The null hypothesis should be accepted. There is not enough evidence to reject the null hypothesis.

The null hypothesis should be rejected.

A hypothesis test has a significance level of 10%. Explain what this significance level represents.

The significance level determines the critical region of the hypothesis test. A significance level of 10% means that there is a 10% probability of rejecting the null hypothesis incorrectly.

Based on the hypothesis test, what conclusion can be drawn about Delmar's claim? Delmar practices at least 2 hours a day. Delmar practices more than 2 hours a day. There is not enough evidence to accept or reject his claim.

There is not enough evidence to accept or reject his claim.

You have reason to believe that there are actually fewer raisins in each box than the company claims. Your alternative hypothesis, mc002-1.jpg, would be

a

What type of significance test should be used for this situation?

a right-tailed test

A basketball coach claims that the team's players commit, on average, no more than 10 fouls per game. Let µ represent the team's average number of fouls per game. Another coach thinks that these players create more fouls. What is the null hypothesis, H0, for this situation?

b

A meteorologist claims that the average daily high temperature in Oklahoma City is 90°F. Let µ represent the average daily high temperature, in °F, in Oklahoma City during the summer. What is the null hypothesis, H0, for this situation?

b

You have reason to believe that there are actually more raisins in each box than the company claims. Your alternative hypothesis, , would be

b

You have sample data that leads you to believe that the average high temperature in Oklahoma City is 92°F. What is the alternative hypothesis, Ha, for this situation?

b

Delmar claims that, on average, he practices the piano at least 2 hours per day. In a hypothesis test of this claim, H0 is µ ≥ 2 and Ha is µ < 2, where µ is the number of hours, on average, Delmar practices daily. The diagram shows the critical region for the hypothesis test. The z-statistic for a sample of Delmar's practice times is 1.41. How should this statistic be interpreted in terms of the hypothesis test? should be rejected. should be accepted. There is not enough evidence to reject .

c

A cereal manufacturer claims that there are an average of 200 raisins in each box of cereal. Let µ represent the average number of raisins per box of cereal. You want to test this claim. What is the null hypothesis, , for this situation?

d